This invention is related to method and apparatus to manage high reliability of data stored in low tier storage systems coupled with high tier storage systems.
In multi tiered storage systems, the system may be configured of a plurality of storage systems having different capacities and performance reliabilities. Users would decide the tier to store the data by its budget, load and importance. To increase data reliability, data correction code may be added to the data, such as disclosed in JP2000-347815. However, when data includes data correction code, low tier storage may not be able to support the added error code. This may effect the total reliability of the system considering data migration within the system.